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bpo-37004: Documented asymmetry of string arguments in difflib.Sequen… · python/cpython@7dafbe8

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  • Misc/NEWS.d/next/Documentation

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@@ -543,6 +543,16 @@ The :class:`SequenceMatcher` class has this constructor:

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to try :meth:`quick_ratio` or :meth:`real_quick_ratio` first to get an

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upper bound.

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.. note::

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Caution: The result of a :meth:`ratio` call may depend on the order of

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the arguments. For instance::

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>>> SequenceMatcher(None, 'tide', 'diet').ratio()

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0.25

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>>> SequenceMatcher(None, 'diet', 'tide').ratio()

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0.5

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.. method:: quick_ratio()

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@@ -0,0 +1 @@

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In the documentation for difflib, a note was added explicitly warning that the results of SequenceMatcher's ratio method may depend on the order of the input strings.